There is no sovereign international body that adjudicates the assignment of sovereignty. Sovereignty means current and actual military power over a particular territory; and through time (centuries and period of civilizations) it passes from one nation to another depending on the tide of superiority of military might. Wu Shicun is stating a solid fact that at present, China has indisputable sovereignty over the waters within the nine dash line. PH, VM, and MY remain in fact the indisputable challengers.
This is my comment in Disqus on the article titled "China expert expects better ties with PH after 2016" (Inquirer, 29 Sept 2014)